1. Field of the Invention
This invention relates to diol compositions.
2. Description of the Prior Art
Thermosetting polyester resinous compositions comprising solutions of an essentially linear unsaturated polyester in a vinyl monomeric crosslinking agent, e.g., styrene, are extensively utilized to prepare molded or cast thermoset plastic articles. The indicated linear polyesters are obtained by condensing an .alpha.,.beta.-ethylenically unsaturated dicarboxylic acid as all or part of the diacid component with a glycol. The bulk of the glycols used for this purpose is propylene glycol.
Where it is desired to impart fire and chemical resistance to the polyester, a halogentated diacid and/or a halogenated diol is generally incorporated into the polyester structure for optimum results. A particularly preferred halogenated compound useful for this purpose is the diol obtained by alkoxylating 3,3',5,5'-tetrabromobisphenol A. In accordance with the prior art, the alkoxylation reaction is carried out in an inert solvent which is removed upon completion of the reaction to provide the compound as a high melting solid which is sold as a powder or solid melt. Removal of the solvent in this manner is costly and moreover provides a product which is difficult to handle in connection with its use to prepare linear polyester resins.